The present invention relates generally to communication coupler devices and more particularly to such devices having magnetic and optical characteristics which allow mating magnetic couplers to be joined for the transfer of information between electronic devices.
The present invention is useful in those types of applications where it is desirable or necessary to electronically communicate with electronic circuitry which is inaccessably housed, such as within a sealed enclosure. To this end, and as a preferred embodiment, the invention finds particular application in utility meters of the computerized electronically programmable type. These types of meters are most frequently designed to be programmed or re-programmed at the place of installation, such as at the customer residence or a commercial business site. Ideally, these types of meters are designed for electronic readout of meter data, for example total kilowatt hour consumption, demand kilowatt consumption and the like.
Programming and reading of the above types of meters is normally done by a utility company meter reader or service person utilizing a portable reader/programmer device. This device is usually provided with some type of plug device for attachment to the meter to enable the reader/programmer to communicate with the electronics inside the meter cover.
The use of an optical coupler for programming meters of the above type is made attractive because of the economic design and manufacturing cost incentives such a coupler affords. A further attractive feature is the high reliability of optical emitter and detector devices employed in such couplers.
One type of optical coupler is shown and described in co-pending U.S. patent application Ser. No. 533,896, which is a continuation of Ser. No. 190,217, filed Sept. 24, 1980 now abandoned and which is assigned to the assignee of the present invention and which is incorporated by reference in the present application as if fully set forth herein. That coupler comprises a first coupler assembly which is rigidly mounted through the meter cover and a second coupler assembly which can be magnetically attached to the first coupler assembly. The coupler is constructed such that precise alignment is maintained between the first and second coupler assemblies when they are magnetically attached to each other while inhibiting the entry of ambient light from entering between the coupled portions.
Although the aforementioned magnetic optical coupler provides an economical and reliable means for communicating with electronic devices which are sealed within a housing or cover, a need exists for a means of signaling the enclosed electronic device that the magnetic coupler has been mated. Such a signal can be used by the enclosed electronic device to enable the optical emitter and detector devices as well as to provide an indication that communication with an external device through the mated coupler is ready to take place. The signaling means should be reliable, tamper resistant, be able to operate through a sealed partition and have no moving parts exposed outside of the partition.